Disk device

ABSTRACT

The object is to keep the system safety even if the disk tray of the disk device is drawn out from the PC main body and led to a structurally dangerous state, and to prevent the disk tray from wrong operation beforehand. In addition, in a recording and playback system for recording and reproducing information on a recording medium such as optical disk, the guide shaft is biased by a bias means that can strongly apply power which doesn&#39;t degenerate, in order to improve the mounting stability, and in addition, to prevent the structural thickness of the entire unit from growing. A disk device composed to execute a load/unload a recording medium by making a disk tray advance and retreat in a chassis case, wherein a first detection switch  5  and a second detection switch  6  for detecting the load of the disk tray  1  are arranged in a way to be on different levels in respect to the operating direction thereof, or they are arranged on a wiring board packaged in the disk tray. Also, a recording and playback system, comprising a head unit composed to record and playback of an information by moving in parallel to the recording face of a recording medium; a guide shafts  10•13  for guiding the translation of the head unit; a bias means for applying bias force to the guide shaft all times; and a retaining means for adjusting the height position of the guide shaft by a drag balanced with the bias force of the bias means, wherein the bias means is composed by inserting a coil parts  22   a   •23   a   •24   a  of a helical torsion springs  22•23•24  into the guide shafts  10•13.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention concerns a bias means of a guide shaft in order to guide the movement of a head unit mainly composed of an optical pick-up of a disk device that drives an optical disk (for instance, CD-R/RW, DVD-R/RW, etc.) as the recording medium for recording a great deal of information in various computer systems and so on, and a recording and playback system built in the computer or audio-visual equipment or diffused as a peripheral unit.

[0003] 2. Detailed Description of the Prior Art

[0004] In general, the PC (hereinafter, it is called PC) cannot lack the disk device for recording/reproduction of information on an optical disk, and so builds it into the PC main body or connects it so called as an external device with the cable.

[0005]FIG. 4 shows the externals of a laptop PC with a built-in disk device, and in general, the Disk device D is built into a side of a main body P of the PC, the part of bezel 102 of a disk tray 101 pops out according to the instruction from the switch operation or the PC, and in addition the user of the PC draws out a disk tray 101 and usually loads the optical disk.

[0006] In such a disk device D, a turntable 103 fixed to a driving shaft of a spindle motor disposed right under is arranged at the center of the disk tray 101 as shown in FIG. 5, the turntable clamps a center hole of the optical disk so as to transmit the turning force. Moreover, a head unit 104 composed mainly of an optical pickup reciprocates radially in a slit 101 a formed in the disk tray for recording and the reproduction information on the optical disk.

[0007] Moreover, the disk tray 101 composed like this is guided by a guide rail 105 and is contained in chassis case 106. The bezel 102 of the disk tray 101 usually inserts a tongue piece 102 a thereof in the main body of the disk tray, fixes by fitting, and in addition screws if necessary.

[0008] Moreover, the recording and playback system, in which the optical disk (for instance, CD-R/RW, DVD-R/RW) that can record a great deal of information, is used as recording medium, is indispensable especially for the PC, and for audio-video equipment, the recording/reproduction of an information is performed using DVD as a recording medium, so the reliability and the durability is highly demanded for the recording and playback system.

[0009]FIG. 4 is the one to show the externals of a laptop PC, and a recording and playback system D is built in a side section of a main body P of the PC, to load and unload an optical disk with a disk tray. In general, the mechanism for loading and unloading the disk tray is omitted, because a laptop PC has to compose extremely flatly, and the disk tray loading is operated as the user pushes it by the finger tip.

[0010] The recording and playback system adopted for such a laptop PC is composed unitarily as shown in FIG. 7, and this also becomes an extremely flat form. In the same drawing, the symbol 101 is a disk tray, and this disk tray is guided to a guide rail 105 and contained in a chassis case 106.

[0011] A turntable 103 fixed to a driving shaft of a spindle motor disposed right under is arranged at the center of the disk tray 101, and a center hole of the optical disk is clamped with this turntable, and the turning force is transmitted. And, the symbol 104 is a head unit mainly composed of the optical pickup, it moves radially in a slit 101 a formed in the disk tray, to record or reproduce information on the optical disk.

[0012] By the way, in general, the head unit 104 is fixed to a head base 104 a, this head base 104 a is slidably attached to a guide shaft, and the head base is composed to translate in a lead groove of a screw shaft, in order to enable a radial movement of the head unit in the disk tray 101.

[0013] The inclination of an optical axis of the optical pickup, inclination of the spindle motor and, especially, mounting displacement of the guide shaft made impossible to determine accurately the relative inclination and distance between the optical pickup and the recording face of the optical disk, in case of such composition. The displacement varies for each finished product, and the attempt to enable the correction of the displacement in the post-processing has been proposed (for instance, Japanese Patent Laid-Open No. 2000-203801).

[0014] As shown in FIG. 11, this consists in arranging a guide shaft 109 so as to be fitted by a seat of an adjusting screw 108 screwed in a chassis 112, and in interposing a helical compression spring 110 between this guide shaft and the chassis, for adjusting the height position of the guide shaft 109 biased upward by rotating the adjusting screw 108. Moreover, in FIG. 9, a leaf spring is interposed to place of the helical compression spring, for adjusting similarly the height position of the guide shaft 109 by rotating the adjusting screw 108.

[0015] Also, in the disk device composed as shown in FIG. 5, the chassis case 106 constituting the fixed part is attached to the PC main body, while the disk tray 101 constituting the moving part advances and retracts in this chassis case 106. Therefore, the opening of the chassis case 106 faces the sidewall of the PC main body, and a gap G is formed between an opening 106 a of the chassis case 106 and a rear end 101 a of the disk tray 101, as shown in FIG. 5.

[0016] By the way, the disk device in the form shown in FIG. 5 a detection switch 108 that detects the retraction momentarily at the time when the disk tray 101 is drawn out from the PC main body by unloading is set in the disk tray 101 as shown in FIG. 6 or is set in a wiring board 107 mounted on the disk tray 101 and the driving state of the disk tray 101 is recognized, or the power supply to a microcomputer of the wiring board mounted on the disk tray is intercepted based on the signal from this detection switch 108, and the system safety of the device has been improved.

[0017] However, if the disk tray is drawn out completely as shown in FIG. 5 when the optical disk is set on the disk tray and loaded, the gap G is created as mentioned above. In such a state, the device is in a state that receives easily danger by the external cause, and has been the one requiring a measure for the system safety.

[0018] That is, for instance, a foreign body such as a piece of paper, etc. might enter the gap G and the detection switch 108 be operated. When this happens, the disk tray 101 enters the state compulsorily loaded though it is unloaded and a turntable 103 and a head unit 104 will be driven.

[0019] The present invention has been devised in order to solve such a problem, to keep the system safety even if the disk tray is drawn out from the PC main body and led to a structurally dangerous state, and to prevent the disk tray from wrong operation beforehand.

[0020] Moreover, as shown in FIG. 11 and FIG. 12, when the guide shaft is biased upward and the height position is adjusted with the adjusting screw, it is preferable that the bias force is as strong as possible in the range where the guide shaft is not deformed. That is, it becomes an important condition that the head unit may never vibrate due to the spring flexion when vibration is applied to the PC main body and, moreover, the spring force does not decrease as time passes

[0021] However, in case of the composition of FIG. 11, it is necessary to increase the turn number of coil of the helical compression spring in order to secure the spring force and, at the same time, satisfactory stress characteristic, therefore, the total length of the helical compression spring becomes long. It is necessary to enlarge structural thickness of the entire unit to interpose this helical compression spring that became longer, and it will influence the thinning of the PC main body. In addition, the height position, that becomes the standard of the guide shaft, will be greatly changed, and a great design change be needed.

[0022] On the other hand, according to the composition of FIG. 12, it is necessary to adopt a leaf spring having a longer spring, in order to secure the spring force and, at the same time, satisfactory stress characteristic similarly to the case of helical compression spring and, therefore, the size of the entire leaf spring grows, and it becomes disadvantageous for the miniaturization. Moreover, because the spring constant was steep, the leaf spring was irregular in bias force, making difficult to obtain a high reliability.

[0023] The present invention offers a bias means that can strongly apply power to the guide shaft and, at the same time, in which the spring force doesn't degenerate, and in addition, is the one to aim to prevent the structural thickness of the entire unit from growing.

SUMMARY OF THE INVENTION

[0024] There, in the present invention, for a disk device composed to execute a load/unload together with a recording medium by making a disk tray advance and retreat in a chassis case, a first detection switch and a second detection switch for detecting the load of the disk tray are arranged in a way to be on different levels in respect to the operating direction thereof, or they are arranged on a wiring board packaged in the disk tray.

[0025] Moreover, the present invention concerns a disk device composed to execute the load/unload together with a recording medium by making a disk tray advance and retreat in a chassis case, wherein a detection switch that detects the disk tray being loaded, is installed in the disk tray, or arranged on a wiring board packaged in the disk tray in such a way that the detection switch be disposed at a position to be covered with the rear end of the disk tray.

[0026] Also, in a recording and playback system, comprising a head unit composed to record and playback of an information by moving in parallel to the recording face of a recording medium; a guide shaft for guiding the translation of the head unit; a bias means for applying bias force to the guide shaft all times; and a retaining means for adjusting the height position of the guide shaft by a drag balanced with the bias force of the bias means, wherein the bias means is composed by inserting a coil part of a helical torsion spring into the guide shaft, to solve the aforementioned problem.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] These and other objects and advantages of the present invention will become clear from the following description with reference to the accompanying drawings, wherein:

[0028]FIG. 1 is a plan view showing the bottom of the disk device according to the present embodiment.

[0029]FIG. 2 is a perspective view showing the disk device of the present invention.

[0030]FIG. 3 is a view showing the mode of the operation of the detection switch of the present invention.

[0031]FIG. 4 is a perspective view showing the laptop PC.

[0032]FIG. 5 is a perspective view showing the composition of the disk device.

[0033]FIG. 6 is a view showing the arrangement of the detection switch in a disk device of the prior art.

[0034]FIG. 7 is a exploded perspective view showing the composition of the recording and playback system of the present invention.

[0035]FIG. 8 is a plan view showing the assembly state of the recording and playback system of the present invention.

[0036]FIG. 9 is a perspective view showing the composition of the bias means according to the present invention.

[0037]FIG. 10 is a side view showing the action state of the bias means according to the present invention.

[0038]FIG. 11 is a side view showing an example of the bias means of a guide shaft of the prior art.

[0039]FIG. 12 is a side view showing another example of the bias means of a guide shaft of the prior art.

DESCRIPTION OF SYMBOLS

[0040]1 . . . Disk tray

[0041]2 . . . Guide rail

[0042]3 . . . Chassis case

[0043]4 . . . Wiring board

[0044]5 . . . First detection switch

[0045]6 . . . Second detection switch

[0046]7 . . . Actuator

[0047]10•13 . . . Guide shaft

[0048]11 . . . Impaction hole

[0049]12•14•15 . . . Reception concave part

[0050]16•17 . . . Reinforcing board

[0051]18•19•20 . . . Adjusting screw

[0052]22•23•24 . . . Helical torsion spring

[0053]25 . . . Screw shaft

[0054]26 . . . Gear unit

[0055]27 . . . Thread motor

[0056]28 . . . Nut

[0057]29 . . . Head base

[0058]30 . . . Optical pickup

[0059]36 . . . Base plate

[0060]70 . . . Spindle motor

[0061]90 . . . Frame member

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0062] Now, embodiments of the present invention shall be described in detail based on drawings. It should be noted that the embodiments described below suppose a composition where the disk device is built into the PC main body, the present invention is not limited to this, but it can also be execute for a disk device of an external type.

[0063]FIG. 1 is a disk device that executes the present invention, showing a state where a shield cover built with a metallic lamina is detached from the bottom face of the disk tray 1 and this disk tray 1 is guided by a guide rail 2 and loaded or unloaded in the chassis case.

[0064] A wiring board 4, that comprises electronic components such as semiconductor integrated circuits, is packaged on this disk tray 1, a driving system unit A to drive the optical disk and the head unit is arranged in the center portion, and an eject/lock mechanism B of the disk tray is set in the corner portion of the front end.

[0065] Next, a first detection switch 5 and a second detection switch 6 are installed on the rear end of the wiring board 4 in different levels, as shown in the same drawing, in respect to the operation direction (direction of the depth) of the switch. Moreover, when the disk tray 1 is pushed into the chassis case 3, and locked with the eject/lock mechanism B, an actuator 7 for operating the first and second detection switches 5, 6, are fixed to the inner wall at the rear end of the chassis case 3 as shown in FIG. 2.

[0066] The symbol 8 is a damper member built into the side of the disk tray 1, and when disk tray 1 is pushed into the chassis case 3, the point 8 a thereof will be brought into slide contact with the inside wall 3 a of the chassis case 3, improving the operation sense of the disk tray by buffering especially horizontal deviation of the disk tray. As for the damper member 8 in the present embodiment, it is possible to afford an important buffering effect, as it is formed meandering the main part.

[0067] The first and second detection switches are connected so that each of double pole points of contact may become in series, and the circuit enters the conductive state only when both detection switches are operated, while the circuit enters the nonconductive state when both or one of detection switches are not operated.

[0068]FIG. 3 is a drawing to explain the operation mode of the first and second detection switches, FIG. 3(A) is a state where the disk tray 1 is unloaded while the first and second detection switches are released from the actuator 7, and therefore, the circuit is in the nonconductive state, because the first and second detection switches are open. Also, FIG. 3(B) is a state where the disk tray 1 is loaded, the first and second detection switches are open by the action of the actuator 7, and the circuit is conductive.

[0069] Moreover, FIG. 3(C) is the one to show the state that such as piece of paper etc. is inserted from a gap G, foreign body P never operates the second detection switch 6, because the foreign body P is inhibited going into any more by the main body of the detection switch 5, though the foreign body P operates the first detection switch 5. Therefore, because the circuit can still maintain the nonconductive state, the system safety to the circuit system of this disk tray can be secured, with the disk tray 1 unloaded.

[0070] Thus, according to the composition of the invention of the present application, at least one of the first detection switch 5 or the second detection switch 6 is arranged at a position covered with the rear end of the disk tray 1 and, moreover covered with the rear end of the wiring board 4 and, consequently, the switches are packaged not to show the externals thereof between the disk tray 1 and wiring board 4, excluding wrong operation other than by the normal action.

[0071] Though, in the aforementioned embodiment, a composition where the first and second detection switches are connected in series, it is not the best to this, and for example, one may be connected to the microcomputer for controlling the disk device, while the other may be connected to the laser power supply line and the spindle motor power supply line.

[0072] Returning to FIG. 1, a wiring board 4, that packages electronic components such as the semiconductor integrated circuits is set in the disk tray 1, and, in addition, a driving system unit A to the optical disk and the head unit are fixed to with a screw 50 in a buffered state.

[0073] As for the driving system unit A, element parts of the driving system are arranged on a base plate 36 molded from a steel plate as shown in FIG. 7 and a spindle motor 70 to rotate and to drive the turntable exposed on the surface of the disk tray 1 is fixed to a frame member 90 with a backing plate 80 at the extremity thereof.

[0074] As for the frame member 90 made integrally of synthetic resin, legs 90 a and 90 b are formed deriving right and left from the fixing portion of the spindle motor 70, a impaction hole 11 of the end part 10 a of the guide shaft 10 is formed on the leg 90 a, and a reception concave part 12 of a small diameter end part is formed in an area where the small diameter end part 10 b of the other end is located. On the other hand, reception concave parts 14 and 15 of this small diameter end part are formed in an area where small diameter end parts 13 a, 13 b of both ends of the guide shaft 13 are similarly located on the leg 90 b.

[0075] Next, symbols 16 and 17 are reinforcing boards, and a screw hole 16 a where an adjusting screw 18 is screwed is formed in the other end part of this reinforcement board 16. Moreover, screw holes 17 a•17 b where adjusting screws 19•20 are screwed are formed at both ends of the reinforcement board 17. Coil parts 22 a•23 a•24 a of helical torsion springs 22•23•24 are pushed into the small diameter end parts 10 b•13 a •13 b of the guide shafts 10•13 as shown in FIG. 8 and, in this state, when the small diameter end parts 10 b•13 a•13 b are contained in the reception concave parts 12•14 15, arms 22 b•23 b•24 b of the helical torsion spring are positioned in grooves 12 a•14 a•15 a of the reception concave part, and the arms 22 b•23 b•24 b come to be supported by projections 12 b•14 b•15 b in the groove (refer to FIG. 10). Besides, the grooves 12 a•14 a•15 a becomes also an fitting portion that prevents the helical torsion spring from being moved in the direction of the shaft axis.

[0076] Thus, the reinforcement boards 16•17 are arranged to cover the guide shaft after the guide shafts 10•13 are arranged in the frame member 90, and the fixing screw 21 screwed in screw hole 36 a of base plate 36, thereby, allowing to fix the frame member 90 and the reinforcement boards 16•17 at the same time. And, when entering such a fixed state, the adjusting screws 18•19•20 at the end part of the reinforcement boards 16•17 will be located as shown in the drawing on the small diameter end parts 10 b•13 a•13 b of the guide shaft. Therefore, the reinforcement boards 16•17 will carry out the function to support the adjusting screws 18•19•20 and the function to improve constructional strength of the entire driving system units A.

[0077] Next, a screw shaft 25 is disposed on the leg 90 a of the frame member 90, and the turning force of a thread motor 27 is transmitted to the screw shaft with a gear unit 26. Therefore, by rotating the screw shaft 25, a nut 28 fitted with the lead groove 25 a thereof follows, and the head base 29 connected to that nut is guided by the guide shafts 10•13 and it reciprocates. Parts of the optical system such as optical picking up 30 are packaged on the head base 29, and they move in parallel to the record face of the recording medium along with the movement of the head base, and recording reproduction of information is performed.

[0078] □ The cost decrease can be achieved by reducing the parts count of the driving system unit A, and □ the accuracy error of the packaging position of the optical pickup 30 supported by the guide shafts 10•13 in respect to the turning centre (namely, disk turning centre) of the spindle motors 70 can be reduced, because it composed to support both ends of the guide shafts 10•13, both ends of the screw shaft 25, threads motor 27, gear units 26, and spindle motors 70 with the frame member 90 thus formed integrally, and consequently, a recording and playback system presenting satisfactory recording characteristics can be provided.

[0079] The present invention is composed as mentioned above, and when the driving system unit A is assembled as shown in FIG. 1, the adjusting screws 18•19•20 of the reinforcement boards 16•17 comes into contact with the top portion of the curved surface of the small diameter end parts 10 b•13 a•13 b of the guide shafts 10•13 as shown in FIG. 10. At this time, the coil parts 22 a•23 a•24 a of the helical torsion springs 22•23•24 is pushed down by the small diameter end parts 10 b•13 a•13 b of the guide shaft, and the arms 22 b•28 b•24 b turns up to be supported by the projections 12 b•14 b•15 b at the position that shown by the solid line of this drawing.

[0080] In a released state where a tensile effect is not imparted, the helical torsion springs 22•23 is equal to the positioning of the arm at the position shown by a virtual line in this drawing, therefore, when it enters the aforementioned state, namely assembly state, a spring force with helical torsion springs 22•23•24 is generated, and a bias force, that pushes up the small diameter end parts 10 b, 13 a, 13 b of the guide shafts 10•13. Then, if the adjusting screws 18•19•20 are rotated to push it down, helical torsion springs 22•23•24 descend as shown by the broken line in this drawing, and, as a result, the adjustment of the height position of the guide shafts 10•13 becomes possible.

[0081] The state is a state where the bias force of the helical torsion springs 22•23•24, that is, the release of spring force is inhibited with the adjusting screws 18•19•20, the stationary pressure by the adjusting screws 18•19•20 become the drag to the bias force and balances, allowing to fix the guide shafts 10•13 to an arbitrary height position. Moreover, it is composed to insert a guide shaft in the coil part of the helical torsion springs 22•29•24 so as to obtain spring force from each of both arms, allowing to obtain an important spring force all the way achieving space-saving.

[0082] It should be noted that, in case of embodiment described hereinabove, an accurate adjustment work is enabled even if what displacement occurs because only the end part 10 a of the guide shaft 10 is maintained by the impaction hole 11 of the frame member 90, and the height position can be individually adjusted at the end part of three other locations assuming this end part to be a standard of the height position.

[0083] As described in detail hereinbefore, according to the present invention, as the interception of the cable run to the disk tray is performed by the first detection switch and the second detection switch arranged in different levels according to the composition of claim 1, the circuit will not become conductive erroneously by a foreign body, and it is possible to make it a highly safe and reliable disk device.

[0084] Moreover, as these the first detection switch and the second detection switch covered with the disk tray according to the composition of claim 2, for instance, mischievous by the infant or others is never invited.

[0085] On the other hand, high reliability can be obtained because enough bias force to the guide shaft is obtained, and the spring force thereof doesn't decrease with time by using the helical torsion spring of a strong spring force. Moreover, because it was assumed the composition in which the coil part of the helical torsion spring is inserted into the small diameter end part of the guide shaft, it does not constitute a factor to thicken the entire, and has a large effect as it is possible to contribute to the thinning and so on.

[0086] While the presently preferred embodiment of the present invention has been shown and described, it will be understood that the present invention is not limited thereto, and that various changes and modifications may be made by those skilled in the art without departing from the scope of the invention as set forth in the appended claims. 

What is claimed is:
 1. A disk device composed to execute a load/unload together with a recording medium by making a disk tray advance and retreat in a chassis case, wherein: a first detection switch and a second detection switch for detecting the load of said disk tray are arranged in a way to be on different levels in respect to the operating direction thereof.
 2. The disk device of claim 1, wherein said first detection switch and said second detection switch are arranged on a wiring board installed in said disk tray.
 3. A disk device composed to execute a load/unload together with a recording medium by making a disk tray advance and retreat in a chassis case, wherein: a detection switch for detecting the loaded state of said disk tray, is installed in said disk tray, in a way to be disposed at a position to be covered with the rear end of the disk tray.
 4. The disk device of claim 3, wherein said first detection switch and said second detection switch are arranged on a wiring board installed in said disk tray.
 5. The disk device of claim 4, wherein said first detection switch and said second detection switch are arranged between said disk tray and said wiring board, and positioned at a position to be covered with the rear end of the disk tray and said wiring board.
 6. A recording and playback system, comprising: a head unit composed to execute the record and playback of an information by moving in parallel to the recording face of a recording medium; a guide shaft for guiding the translation of said head unit; a bias means for applying bias force to said guide shaft all times; and a retaining means for adjusting the height position of the guide shaft by a drag balanced with the applying bias force of said bias means, wherein; said bias means is composed by inserting a coil part of a helical torsion spring into said guide shaft.
 7. The disk device of claim 6, wherein: said guide shafts are a first guide shaft and a second guide shaft; and said retaining means for adjusting the height of said guide shaft is installed in three spaces of four places of respective both ends of said first and second guide shafts.
 8. The recording and playback system of claim 6, wherein: said guide shaft is tapered to the end portion; and said bias means is composed by inserting a coil part of a helical torsion spring into the tapered portion of said guide shaft.
 9. The recording and playback system of claim 6, having a support member for supporting said guide shaft, wherein: a fitting portion (grooves 12 a, 14 a, and 15 a in the embodiments) that fits the end portion of said helical torsion spring and prevents the helical torsion spring from moving in the axial direction of said guide shaft is formed in said support member. 